An ant is trapped in an 6x4 board with squares (looking at the shape of the board, we have 6 squares horizontally and 4 vertically).
Starting from the bottom left square and moving only horizontally and vertically through the squares (not diagonally), is it possible that it reaches the top right square so that it is set free?
Note that the ant must pass from every single square and only ONCE!
If it is possible, explain the pattern, otherwise, explain why it cannot be done.
(no matter how hard I've tried, I haven't made it, so, by intuition only, I assume it cannot be done - but I need an explanation).